European Soil Becoming More Resistant to Antibiotics

Image credit: plindberg/FlickrOutbreaks of MRSA, swine flu, and other diseases point directly to a need to improve the conditions under which we produce food, and an increased scrutiny of what we add back to the environment.

In Europe, a continent-wide campaign to reduce the number of antibiotics released into the environment is underway with the goal of reducing the chances for a MRSA-like "superbug" to emerge. Despite these efforts, recent research indicates that background levels of antibiotics in the soil are actually increasing.David Graham, a professor at Newcastle University, led a study that compared data from soil samples taken between 1940 and 2008. Looking at bacterial DNA, he found that the number of antibiotic genes increased during this period.

He explained that "over the last few decades there has been growing concern about increasing antibiotic resistance and the threat it poses to our health, which is best evidenced by MRSA." He went on to say that:

Despite increasingly stringent controls on our use of antibiotics, the background level of antibiotic resistant genes, which are markers for potential resistance, continues to rise in soils...this increases the chances of a resistant gene in a harmless bacteria being passed onto a disease-causing pathogen, such as a MRSA, with obvious consequences.

His research found that 78 percent of genes from four common classes of antibiotics showed increases. Why levels continue to increase in spite of restrictions on the use and disposal of antibiotics in agriculture and medicine remains unknown.

One thing that is clear, Graham explains, is that the risk of resistant genes passing from environmental organisms to those of "greater health concern" is increasing.